Cruise Ship Roller Coaster On the Simpsons

Last night's episode of the yellow people had the family taking a cruise on a mega-ship. The ship featured, among many other amenities, a large roller coaster. There were no close-ups, but it appeared to be wood. When things on the ship were rotting/deteriorating (long story) the coaster appeared (in the background) to be crumbling and a train flew off the tracks and into the ocean. Not on the level of previous Simpson park/coaster gags (Hello, Zoominator!) but a pretty cool idea nonetheless.